For example, newspaper publishing companies that publish news papers over a wide area such as the whole country, to deliver the latest possible information to subscribers, generally adopt a system in which the editing of pages is collectively performed in the head office, while the printing of newspapers is performed in newspaper printing factories established in various places. In this case, newspaper printing factories receive the edited data from the head office through communication between them and, based on the printing data, make printing plates to carry out printing.
For instance, in a system such that the head office and newspaper printing factories of a newspaper publishing company are connected through a known network, the head office performs the editing of newspapers by an edit system that is used for compound media containing not only newspapers but also other media. The result of the editing is stored in the server of the head office as printing data and transmitted from the server to the newspaper printing factories.
In the newspaper printing factories, after a data server in each of the newspaper printing factories receives the printing data from the head office, the factory management system makes printing plates based on the received data. In the platemaking, for example, a CTP (Computer-To-Plate) machine or CTF (Computer-To-Film) machine is employed. In the CTP machine, a printing plate is output directly from the digital data. In the CTF machine, because a platemaking film is first output, a printing plate is made based on this film. The printing plate thus made is put on the corresponding plate cylinder of a rotary newspaper printing machine by hand.
Newspaper printing is particularly requested to not only provide subscribers with the latest information quickly but also provide information accurately. The newspaper printing is also requested to reproduce and provide image information with high fidelity as well as not to provide wrong character information. Because color printing of newspaper pages has recently been performed, it is necessary to reproduce color image information with high fidelity.
Conventionally, in a general printing machine such as a planographic offset printing machine, the platemaking step and printing plate step are separated from the printing step, and printing plates to be used are often made by analog exposure. For that reason, the above-described digital data for pages that are used in making printing plates are not employed in the printing management and printing control that are performed in the printing step. However, in recent years, at the request for time-saving for printing and an enhancement in print quality, there has been proposed a technique in which efficient printing and high quality are obtained by using the digital data (platemaking data) of page information in the tone control of printed matter that is performed in the printing step, specifically the presetting control of the ink keys of the printing machine.
For example, Patent Document 1 disclose a technique in which the quantity of ink to be supplied to a printing machine is controlled based on platemaking data by feeding back information detected by an IRGB densitometer. In this way, the tone of printed matter can be controlled immediately after the start of the printing machine, based on the platemaking data. Therefore, the time to initiate tone control is shortened, whereby the operating efficiency can be increased.    Patent Document 1: Japanese Patent Application Laid-Open No. 2004-106523